Weighed charge system for a brick press

ABSTRACT

A system to deliver a weighed charge to the mold box of a brick press so that the material is uniformly distributed in the mold is disclosed. Specifically, a weighed charge is conveyed to the mold by conventional means, but is distributed in the mold by the coordinated synchronous movement of both the lower press pad&#39;&#39;s downward motion and the reciprocating action of the charger during the charging sequence.

United- States Patent [191 Platt [111 3,811,808 [451 -May 21, 1974WEIGHED CHARGE SYSTEM FOR A BRICK PRESS [75] Inventor: Richard O. Platt,Bethel Park, Pa. [73] Assignee: Dresser 1ndustries,1nc., Dallas, Tex.[22] Filed: Feb. 22, 1971 [21 App]. No.: 117,587

[52] US. Cl. 425/167, 425/352 [51 Int. Cl. B29c 3/06 [58] Field ofSearch 425/253, 255, 356, 412, 425/413, 344, 351 398, 406, 352, 354,355, 148, 77, 78,422, 260, 411, DIG. 33, 416; 264/294, 109; 25/103 [56]References Cited UNITED STATES PATENTS 297,218 4/1884 Andrus 425/344478,915 7/1892 'Burkman 425/344 X 642,581 2/1900 C allaway 425/344985,153 2/1911 Flood 425/344 1,241,398 9/1917 Kespohl 425/344 X3,213,511 10/1965 Petruzzi 425/448'X 1,000,823 7 8/1911 Leflaive r425/352 3,050,809 8/1962 Kupha...- 425/352 10/1966 Neubauer 425/355?25,939 9/1885 Kennedy 425/344 X 480,818 8/1892 Koch 425/344 X 3,187,4016/1965 ODonnell... 425/148 3,690,805 9/1972 Kopicko 425/344 X 987,1243/1911 Flood 425/344 X 2,888,731 6/1959 McElroy 425/167 X 3,107,410,10/1963 Davis 425/159 3,368,254 2/1968 Schacht 425/167 3,563,654 2/1971Steingroever.... 425/411 X 3,397,435 8/1968 .lelesiewicz 425/411 X3,555,621 1/1971 Hara 425/78 X Primary Examiner--J. Spencer OverholserAssistant Examiner-John S. Brown [5 7] ABSTRACT 4 Claims, 7 DrawingFigures P ENIEnm 21 1924 3.81 1.808

SHEET 2 UF 2 I7 l8 I II l4 FIG. 5

RICHARD O. PLATT INVENTOR ATTORNEY l WEIGHED CHARGE SYSTEM .FOR A BRICKPRESS 1 Many of the important properties of. refractory bricks aregoverned by their bulk density, the control of which will depend on thesuccess in feeding'the same weight sequence by adjusting the one of themodifications of the Boyd-type press accordof uniformly mixed materialto each mold box at each pressing. However, with ,many of the presentbrick press charging devices, segregation of the batch or uneven moldfilling occurs which results in pressed brick of nonuniform properties.In addition, poor mold filling can result in an excess of entrapped airin the batch which can lead to problems such as cracking during andafter the pressing cycle.

Accordingly, it is among the objects of this invention to provide amethod and apparatus for uniformly filling a mold box with a refractorybatch. It is another object of the invention to provide apparatus formodification of existing brickmaking presses, whereby brick ofsubstantially uniform thickness, density and porosity can be made from agiven refractory batch.

Briefly, according to this invention, there is provided apparatus formodification of a brick press, whereby brick of substantially uniformproperties can be obtained from a givenrefractory batch. The apparatusincludes means arranged to deliver accurately weighed quantities ofgranulated brick material to a mold'charging system which evenlydistributes the material in the mold box. An example of a mechanicalbrick press, which can be modified according to this invention, isshown, for example, in U.S. Pat. No. 987,124. This is sometimes called aBoyd-type press.

Other objects and further features and advantages of the invention willbecome apparent to those skilled in the art from a study of thefollowing detailed description, with reference to the drawings. In thesedrawings:

FIG. 1 is a side elevation in partial section of apparatus according tothis inventionusedwith a brick press;

FIGS. 2'to 5 are partial cross'sectional views of the mold box chargingarid'pressing area illustrating four stages of the pressing cycle;

FIG. 6 is a hydraulic schematic diagram showing a series of solenoidsand valves for actuationof the lower 'press pad situatedin the mold boxand for the charging cylinder; and,

FIG. 7 is anelectrical diagram illustrating a means for synchronizingthe'operation of the press.

Those portions of a Boyd-type mechanical brick press which are shown inFIG. 1 include a worktable 15 provided with a rectangular molding cavityor mold box 16. The pressing of brick shapes in the mold box isaccomplished by the movement of the upper and lower pressure plates orpads 18 and 19 attached to the upper and lower plungers l7 and 20,respectively. The lower plunger rests on a saddle plate 21 which in turnis disposed on a lower crosshead 22. The upper plunger is movedvertically by a crosshead (not shown) slidably mounted in guides (notshown)at opposite sides of the press frame (not shown). Anexemplaryconstruction for the upper portion of a brick press in shown inU. S. Pat. No. 2,893,101, and it is incorporated herein by reference.

In order to control the brick size in a conventional Boyd-type press,the operator would have adjusted, by a mechanical linkage, the depth ofthe mold for the fill ing to my invention. A hydraulic cylinder 24 isinstalled in the lower crosshead in place of the usual springs andmechanical linkage to control the downward motion to the saddle plateduring the charging sequence. The bydraulic cylinder (saddle cylinder)24 with an extended piston rod 23 and a mounting flange 25 at the rodend is mounted at the bottom of and on the centerlines of the lowercrosshead 22. The top of the rod is connected to the saddle plate via athreaded hole 26. This arrangement allows the control of the travel ofthe lower pad which aids the brick mix in being uniformly distributed inthe mold cavity.-

The automatic batch feeding system comprises an automatic scale andhopper 10 which dispenses a desired amount of material 11 onto aconveyor comprising an endless belt feeder 12. The belt feeder deliversthe material to the charger 14 and may be supported by the frame of thebrick press or independently. The horizontal movement of the charger iscontrolled by the charger-cylinder 13, which provides reciprocatingmovement of the charger back and fourth across the mold box which, incombination with the controlled downward movement of the lower pad, isthe crux of this invention. The cylinder 13 contains a piston 30 and rod31 which may be reciprocated by hydraulic fluid schematicallyillustrated in FIG. 6 or compressed air.

In FIG. 2, the lower pad 19 is raised to a relatively high position inthe mold. box. As the sequence is begun, the charger 14 distributesmaterial 11 into the mold box 16 on the first stroke of the cylinder 13.The charger on the initial stroke delivers only a portion of the chargeto themold. After this first pass, the lower pad begins its descentwhich is synchronized with the reciprocating speed of cylinder 13 andmold box 16. The charger, on thefirst stroke, is moved horizontally sothat the rear side has passed the mold centerline. At this time thesaddle cylinder 24 lowers the saddle plate 21 slowly to provide morespace forthe material in the mold- At the same time the charger on itssecond stroke, moves horizontally until the front side has passed thecenterline as shown in FIG. 3. Simultaneous lowering of the saddle andreciprocating motion of the charger is continued, and the mold is morecompletely filled. The sequential charging operation with synchronizedlower pad positioning is continued until the mold is completely filledwith layered portions.

. In FIG. 2, the space 32 between the top of the crosshead 22 and thesaddle 21 indicates that the saddle cylinder piston rod 23 is at theupward end of its stroke, whereas in FIG. 3 the saddle cylinder pistonrod is near the lower end of its stroke. In FIG. 4, the mold has beencompletely filled, and the upper pad has descended and has compressedthe material between it and the lower pad 19. The saddle 21 now rests ontop of the crosshead 22. In FIG. 5, the pressed brick is being ejectedby simultaneous upward motion of the lower crosshead through thecontrolled upward motion of the saddle the press cycle continues. Thelower crosshead drops and, during its downward travel, the saddlecylinder piston rod moves up elevating the lower pad to a relativelyhigh position in the mold so that the first charger stroke partiallyfills the mold. The charger starts reciprocating strokes distributingmaterial in the mold while the lower pad is simultaneously lowered bythe saddle cylinder piston rod and so on.

The cylinders 13 and 24 which have double acting pistons may be actuatedas shown by the schematic diagram of FIG. 6. The cylinders 13 and 24contain pistons 30 and 34 and attached rods 31 and 35, respectively. Forthe cylinder 24, the hydraulic fluid is fed to the cylinder underpressure from a reservoir 36 by a conventional pump 37. The fluid passesthrough a directional control valve 38 for the controlling of thedirection of motion of the cylinder piston (up or down). This action ofthis valve may be controlled by solenoid 39. From valve 38, the fluidpasses into one of the flow control valves 40 or 41. Valve 40 controlsthe downward motion of the lower pad. Valve 41 controls the upwardmotion of the lower pad when the pressed brick is being ejected.

For the cylinder 13, the hydraulic fluid also passes through adirectional control valve 42 controlled by a solenoid 43. However, here,the fluid passes directly into the cylinder since the mold boxreciprocates rapidly with reference to the lower pad.

The hydraulic system could contain other components, i.e., pressuregauge, pressure relief valves, other solenoids, a fluid accumulator,filter and the like. However, these are not shown or discussed for thesake of brevity and since these are well known in the art. Manydifferent hydraulic systems could be used to control the action of thepistons within the cylinders.

As mentioned previously, all of the steps in pressing brick shapes aresynchronized for sequential operation. H6. 6 illustrates an exemplaryschematic electrical circuit for controlling the sequence of steps. Amultiple cam timing switch is represented by three earns 50, 52 and 53.Each cam actuates valves 42, 38 and clutch 44, respectively, throughtheir respective solenoids 43, 39 and 45. In practice, the cams may bemounted on a common shaft for rotation thereon. A voltage (V) is appliedacross the circuit from a source separate from that normally associatedwith the press. This circuit may be integrated with the press circuitand other components attached to the press. However, modifications wouldhave tobe made to the entire circuit as is well known in the art, andvarious other operative circuity is possible.

When the operator at the press starts the switch for operation, all camson the common shaft will rotate together. Cam 50 with the lead contact(a) will first close the switch and cause the charger 14 to move forwardover the mold box 16. The opening of the switch will cause the chargerto move back across the mold box to its starting position. The repeatedopening and closing of the switch throughout the half cycle of this camprovides the reciprocal movement of the charger.

Shortly after the contact (a) of cam 50 closes the switch, contact (b)of cam 52 closes a switch and causes the descent of lower pad 19. Thisdescent is slow and continuous throughout an approximate half cycle ofthis cam.

When the descent is complete, contact (c) of cam 53 will activate aclutch on the clutch on the press which will in turn activate themechanical linkages in the press to cause the upper pad 18 to descendand compress the material in the mold box. (For example, see U. 8. Pat.No. 2,893,101.) The opening of the switch causes the pad 18 to retract.v

At this point, contact (d) of cam 52 closes a switch which, through thehydraulic system, forces the lower pad upward to eject the compressedshape and position itself for the next cycle.

While illustrating my invention in connection with a Boyd-typemechanical press, it is readily applicable to other presses, whethermechanical or hydraulic type.

Having thus described the invention in detail and with sufficientparticularity as to enable those skilled in the art to practice it, whatis desired to have protected by Letters Patent is set forth in thefollowing claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. In combination with a brick press having a mold box and a verticallymovable upper press pad, means for accurately weighing quantities ofgranular material, means for charging said weighed material to the moldbox by continuous reciprocal movement, a vertically movable lower presspad within the mold box, electrical means synchronized with thereciprocation of the charging means for lowering the lower press padwhile the mold box is being filled by the charging means with a seriesof continuous reciprocating strokes, means for lowering the upper padinto the mold box after the lower pad has ceased descending to compressthe grandular material into a shape between the upper and lower pads,means for raising the upper pad and means for raising the lower pad toeject the compressed shape.

2. The combination of claim 1 which includes means for synchronizingsequential movement of the charging means, lower press pad and upperpress pad.

3. The combination of claim 1 in which the vertical movement of thelower pad and the reciprocal movement of the charging means is providedby a double action piston contained within a pressure cylinder.

4. The combination of claim 3 in which the pressure is provided byhydraulic fluid.

1. In combination with a brick press having a mold box and a verticallymovable upper press pad, means for accurately weighing quantities ofgranular material, means for charging said weighed material to the moldbox by continuous reciprocal movement, a vertically movable lower presspad within the mold box, electrical means synchronized with thereciprocation of the charging means for lowering the lower press padwhile the mold box is being filled by the charging means with a seriesof continuous reciprocating strokes, means for lowering the upper padinto the mold box after the lower pad has ceased descending to compressthe grandular material into a shape between the upper and lower pads,means for raising the upper pad and means for raising the lower pad toeject the compressed shape.
 2. The combination of claim 1 which includesmeans for synchronizing sequential movement of the charging means, lowerpress pad and upper press pad.
 3. The combination of claim 1 in whichthe vertical movement of the lower pad and the reciprocal movement ofthe charging means is provided by a double action piston containedwithin a pressure cylinder.
 4. The combination of claim 3 in which thepressure is provided by hydraulic fluid.